What does it take to start an egg donor company in your 20s, lead an IT business in your 30s, grow an oil products company in your 40s or reinvent yourself as head of an Internet firm in your 50s?

Forbes Magazine has just finished a series of entrepreneurial stories about women of various ages, including: Diane Hessan, Kathy Lehne, Cassandra Sanford and Julia Alkire & Stephanie Goldman. Here are the stories:

Entrepreneurial success in your 50s: Diane Hessan, president and CEO of Internet firm Communispace, creating social communities.

Entrepreneurial success in your 40s: Kathy Lehne, founder of oil products company SunCoast Resources.

Entrepreneurial success in your 30s: Cassandra Sanford, Co-founder and CEO of KellyMitchell

Entrepreneurial success in your 20s: Julia Alkire & Stephanie Goldman of Family Creations